The PI performs research in the area of vascular biology with emphasis on the role of fluid forces in regulating cell and biomolecule function. His laboratory develops and applies quantitative experimental methods to complement traditional methods in molecular biology and hematology in order to gain novel insight into the pathways regulating leukocyte-endothelial cell adhesion and thrombosis mechanics. In the long run, we aim to apply this understanding of biological mechanisms and fluid-flow mediated phenomena to develop new drugs and therapeutic strategies designed to treat vascular diseases. Some aspects of this work are funded by the NHLBI R01 grant HL63014. In recent experiments, we applied our quantitative experimental strategies to study shear-induced platelet activation. Here we observed using static and dynamic light scattering, that fluid shear in addition to regulating cell function, may also regulate bio-molecular structure. In this study, fluid forces induced the self-association of plasma protein von Willebrand Factor (vWF). We study this observation in greater detail in the current proposal. The objective of the training component of this proposal is to obtain formal training in methods that can be used to study biomolecule structure and function under shear. These methods include light scattering, small-angle X-ray and neutron scattering, surface plasmon resonance and molecular simulations. Some aspects of the training require the PI to attend graduate-level courses and workshops in areas including research ethics. Other aspects of training are unstructured, and they involve self-study by the PI and interactions with collaborators. The specific research goals of the project are: 1) to study the dynamic structure of plasma vWF under shear using light, neutron and X-ray scattering, 2) to quantify the rate and shear dependence of vWF self-association in a milleu that mimics in vivo conditions using surface plasmon resonance, and 3) to determine the structural features of biomolecules that make them susceptible to conformational alteration upon application of physiological and pathological fluid forces. This is achieved by combining the experimental knowledge obtained from the above studies with theoretical methods in molecular simulations and other computational techniques. In the long run, the studies aim to provide new mechanistic insight and therapeutic strategies to counter cardiovascular diseases.